Year	per person
1800	1.181
1820	1.181
1913	2.178
1970	8.66
1971	9.076
1972	9.504
1973	10.08
1974	10.25
1975	9.61
1976	8.754
1977	9.473
1978	9.945
1979	11.2
1980	12.13
1981	12.9
1982	13.1
1983	14.15
1984	15.4
1985	16.87
1986	18.67
1987	20.78
1988	22.86
1989	24.59
1990	25.38
1991	25.77
1992	25.61
1993	26.4
1994	27.36
1995	25.55
1996	26.55
1997	27.17
1998	27.66
1999	28.13
2000	27.94
2001	28.01
2002	28.23
2003	29.27
2004	30.95
2005	31.97
2006	35.7
2007	37.6
2008	37.85
2009	34.94